A 65-year-old male patient with a history of chronic kidney disease and hypertension was admitted to the ICU with severe metabolic acidosis. Despite standard medical therapy, his peripheral venous blood gas analysis shows pH: 7.23, base excess [BE]: -4 mEq/L, PaCO2: 32 mm Hg, and lactate: 6 mmol/L. The medical team decided to administer sodium bicarbonate to correct the acidosis.

Wrong Answer: a) Improvement in kidney function

Explanation:
While sodium bicarbonate may help in some cases, it's not guaranteed to improve kidney function significantly in all ICU patients with metabolic acidosis. It may avert the need of CRRT.

Wrong Answer: b) Correction of acidosis

Explanation:
This is one of the primary benefits of sodium bicarbonate therapy, not a risk. It helps increase blood pH levels. However, it may potentiate paradoxical exacerbation of intracellular acidosis, with resultant organ decompensation.

Right Answer: c) Potentiation of lactic acidosis

Justification:
● Increased Lactic Acid Production: Sodium bicarbonate therapy can sometimes lead to an increase in lactic acid production, which is a concern because it can exacerbate metabolic acidosis rather than alleviate it. This occurs due to the shift in the body's acid-base balance, leading to possible complications. A retrospective analysis published in PLOS ONE found that sodium bicarbonate administration was associated with higher mortality rates in patients with lactic acidosis.1
● Other Potential Risks: Sodium bicarbonate can also cause other adverse effects such as hypocalcemia (low calcium levels) and hypertonicity, which can negatively impact cardiac function.

Clinical Pearls regarding “role of sodium bicarbonate in metabolic acidosis in ICU patients”:

Selective Use: Sodium bicarbonate should be used selectively in patients with severe metabolic acidosis (pH < 7.20) and AKI stage 2/3 and those who do not respond to other treatments.
Monitor for Complications: Be vigilant for potential complications such as hypocalcemia, increased lactic acid production, and fluid overload.

Consider Renal Replacement Therapy: In cases where sodium bicarbonate is not effective or contraindicated, consider renal replacement therapy as an alternative approach. Evaluate Patient Response: Regularly monitor patient response to therapy, including blood pH levels, electrolyte balance, and overall clinical status.
Evidence-Based Approach: Evidence for the routine use of sodium bicarbonate in ICU patients with metabolic acidosis is limited and its effect on patient outcomes remains unclear. Its application should be evaluated based on individual patient needs until results from the recently completed BICAR-ICU-2 Trial are published.

Wrong Answer: d) Reduction in ICU mortality

Explanation:
Current evidence from clinical trials like the SODa-BIC Trial shows no significant difference in ICU mortality between patients who received sodium bicarbonate and those who did not.2 However, findings from the large trial (BICAR-ICU) suggest that In a subgroup of patients with AKI (with Acute Kidney Injury Network scores of 2 or 3 at enrolment), bicarbonate administration reduced the occurrence of a composite of death from any cause by day 28 and the presence of at least one organ failure at day 7. (3)

Reference:

1. Kim HJ, Son YK, An WS. Effect of sodium bicarbonate administration on mortality in patients with lactic acidosis: a retrospective analysis. PloS one. 2013 Jun 5;8(6):e65283.
2. Neto AS, Fujii T, McNamara M, Moore J, Young PJ, Peake S, Bailey M, Hodgson C, Higgins AM, See EJ, Secombe P. Sodium bicarbonate for metabolic acidosis in the ICU: results of a pilot randomized double-blind clinical trial. Critical Care Medicine. 2023 Nov 1;51(11):e221-33.
3. Jaber S, Paugam C, Futier E, Lefrant JY, Lasocki S, Lescot T, Pottecher J, Demoule A, Ferrandiere M, Asehnoune K, Dellamonica J. Sodium bicarbonate therapy for patients with severe metabolic acidaemia in the intensive care unit (BICAR-ICU): a multicentre, open-label, randomised controlled, phase 3 trial. The Lancet. 2018 Jul 7;392(10141):31-40.